Process having dynamic subqery in for loop cursor

Question

I created a process that puts all retrieved rows into a collection. Users can select on quite a few columns, say unit, last_name, shift, etc. When the query is built based on users' inputs, I can't get it working using a For Loop Cursor (code 3.). But I tried and found out that sample 1 is working while sample 2 is not.
Can anyone please help? give advices or point to the right direction?
Thanks very much in advance!!!
DC
sample 1, works:
begin
:P8_TEST_CURSOR := '';
for c in ( select ename from emp ) loop
:P8_TEST_CURSOR := :P8_TEST_CURSOR || ', ' || c.ename;
end loop;
end;
sample 2, does not work:
declare
q varchar2(2000) := 'select ename from emp';
begin
:P8_TEST_CURSOR := '';
for c in q loop
:P8_TEST_CURSOR := :P8_TEST_CURSOR || ', ' || c.ename;
end loop;
end;
code 3, my actually pursuing code, sorry it's long:
declare
q varchar2(2000);
v_unit_id cpd_units.id%TYPE;
begin
q := 'select distinct e.user_id
, nvl(to_char(law_common.get_star_no(e.id)), ''-'') star_no
, nvl(e.last_nme, ''-'') last_name
, nvl(e.first_nme, ''-'') first_name
, nvl(e.MIDDLE_INITIAL, ''-'') middle_initial
, e.employee_no
, nvl(to_char(e.employee_position_cd), ''-'')
, nvl(w.uod_cd, e.cpd_unit_assigned_no) unit
, nvl(w.watch_cd, ''-'')
from cpd_employees e, dpv2wtch w
where e.status_i = ''Y''
and nvl(e.resignation_date, sysdate) >= sysdate
and e.employee_position_cd in (''9112'', ''9152'', ''9153'', ''9155'', ''9161'', ''9164'')
and e.user_id is not null
and w.ssn_no(+) = e.ssn
and e.user_id not in (select c001
from htmldb_collections
where collection_name = ''ACTIVITY''
if :P300_STAR_NO is not NULL then
q := q || ' and e.id = law_common.get_employee_id(:P300_STAR_NO)';
--q := q || ' and law_common.get_star_no(e.id) = :P300_STAR_NO';
end if;
if :P300_EMPLOYEE_NO is not NULL then
q := q || ' and e.employee_no = :P300_EMPLOYEE_NO';
end if;
if :P300_USER_ID is not NULL then
q := q || ' and e.user_id = :P300_USER_ID';
end if;
if :P300_LAST_NAME is not NULL then
q := q || ' and upper(e.last_nme) like ''' || upper(:P300_LAST_NAME) || '%''';
end if;
if :P300_FIRST_NAME is not NULL then
q := q || ' and upper(e.first_nme) like ''' || upper(:P300_FIRST_NAME) || '%''';
end if;
if :P300_EMPLOYEE_POSITION_CD is not NULL then
q := q || ' and e.employee_position_cd = :P300_EMPLOYEE_POSITION_CD';
end if;
if :P300_UNIT is not NULL then
q := q || ' and nvl(w.uod_cd, e.cpd_unit_assigned_no) = :P300_UNIT';
end if;
if :P300_WATCH_CD <> 'NULL' then
q := q || ' and w.watch_cd = :P300_WATCH_CD';
end if;
--htp.p('Limit Unit '||:P0_LIMIT_UNIT);
/* authorization of editing OWN, UNIT, or ALL recs */
if substr(:P0_PERMISSION, 1, 5) = 'QUERY' then
q := q || ' and e.user_id = v(''FLOW_USER'')';
elsif substr(:P0_PERMISSION, -4, 4) = 'UNIT' then
q := q || ' and coalesce(w.uod_cd, e.cpd_unit_assigned_no)= :P0_LIMIT_UNIT ';
end if;
htp.p('q: ' || q);
cursor q_c is q;
for c in ( q_c ) loop /* HOW CAN BE DYNAMIC ???? */
l_seq_id := htmldb_collection.add_member(
p_collection_name => 'OFFICER_ACTIVITY'
, p_c001 => c.user_id
, p_c002 => c.star_no
, p_c003 => c.last_name
, p_c004 => c.first_name
, p_c005 => c.middle_initial
, p_c006 => c.employee_no
, p_c007 => c.employee_position_cd
, p_c008 => c.unit
, p_c009 => c.watch_cd
, p_c050 => :P0_APP_USER
end loop;
end;

Answer 1

Come back to solve my need. I get the working test process:
declare
type ty_cursor is ref cursor;
my_cursor ty_cursor;
my_rec emp%rowtype;
l_num number := 7900;
q varchar2(2000) ;
l_using varchar2(200) := null;
begin
:P8_TEST_CURSOR := '';
q := 'select * from emp';
if :P8_ENAME is not null then
q := q || ' where ename like :P8_ENAME';
l_using := ':P8_ENAME';
end if;
if l_using is not null then
open my_cursor for q using :P8_ENAME; --l_using;
else
open my_cursor for q;
end if;
loop
fetch my_cursor into my_rec;
exit when my_cursor%notfound;
:P8_TEST_CURSOR := :P8_TEST_CURSOR || ', ' || my_rec.empno;
end loop;
end;
But I need
open my_cursor for q using l_using;
to be working since my application has several searchable columns for users and I have to put users' input search into l_using. It does NOT work: q got 'select * from emp where ename like :P8_ENAME' and l_using got ':P8_ENAME' at "open ...." statement.
How can I get this cursor opened dynamically?
Thanks again!
DC